• Computers and Concrete
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• 제23권1호
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• pp.25-36
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• 2019

In this paper, an algorithm is presented to simulate numerically the reinforced concrete (RC) columns having any geometric form of section, loaded eccentrically along one or two axes. To apply the algorithm, the columns are discretized into two macro-elements (MEs) globally and the critical sections of columns are discretized into fixed rectangular finite elements locally. A proposed triple simultaneous dichotomy convergence method is applied to find the equilibrium state in the critical section of the column considering the three strains at three corners of the critical section as the main characteristic variables. Based on the proposed algorithm a computer program has been developed for simulation of the nonlinear behavior of the eccentrically-loaded columns. A good agreement has been witnessed between the results obtained applying the proposed algorithm and the experimental test results. The simulated results indicate that the ultimate strength and stiffness of the RC columns increase with the increase in axial force value, but large axial loads reduce the ductility of the column, make it brittle, impose great loss of material, and cause early failure.

• 한국시뮬레이션학회논문지
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• 제9권2호
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• pp.15-25
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• 2000

Since data security problems are very important in the information age, cryptographic algorithms for encryption and decryption have been studied for a long time. The GOST(Gosudarstvennyi Standard or Government Standard) algorithm as a data encryption algorithm with a 256-bit key is a 64-bit block algorithm developed in the former Soviet Union. In this paper, we describe how to design an encryption chip based on the GOST algorithm. In addition, the GOST algorithm is compared with the DES(Data Encryption Standard) algorithm, which has been used as a conventional data encryption algorithm, in modeling techniques and their performance. The GOST algorithm whose key size is relatively longer than that of the DES algorithm has been expanded to get better performance, modeled in VHDL, and simulated for implementation with an CPLD chip.

• 제어로봇시스템학회논문지
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• 제19권3호
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• pp.248-255
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• 2013

This paper proposes the architecture of the RILS (Robot-in-the-Loop-Simulation) consisting of the robot, the virtual robot, and the avatar robot which is the type of virtual robots operating according to the robot status and behavior. And the synchronization algorithm for mobilization part of the avatar robot is suggested, which reduces the difference between behaviors of the robot and those of the avatar robot. This difference occurs due to the environmental and mechanical mismatches between the robot and avatar robot. In order to reduce this difference in robots behaviors, the synchronization algorithm controls the avatar robot based on the data observed from the robot's behavior. The proposed architecture and the synchronization algorithm are validated from some simulation results.

• 한국정밀공학회지
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• 제21권2호
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• pp.52-59
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• 2004

In this paper, the automatic system generation algorithm based on the element combination algorithm discussed in the first part of this paper for designing an arbitrary type of the automatic transmissions is proposed. The powertrain design software using these algorithms is developed. This automotive powertrain design software with user-friendly graphic user interface has two main modules. The first module, the automatic power flow generation module, is already discussed in the previous paper. The second module dealing with the automatic system generation algorithm is discussed in this paper. The power-flow simulation software fur the arbitrary type of powertrain is then developed. The simulation and experimental results of the vehicle equipped with two planetary gear type automatic transmission are compared to validate the proposed algorithms and developed software. The simulation results demonstrate the good agreement with the experimental results.

• 한국CDE학회논문집
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• 제13권1호
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• pp.67-75
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• 2008

In spite of rapidly increasing interests in digital manufacturing, there still lacks of a systematic approach in manufacturing line flow analysis via modeling and simulation; currently, the parameters for designing manufacturing line are defined by being solely based on engineers experiences. The paper proposes an application of the genetic algorithm to a discrete event line simulation finding optimal set of parameters for manufacturing line balancing problem. The proposed method has been applied to two example problems-one is a simple manufacturing model and the other for shipyard industry-in order to demonstrate its validity and usefulness.

• 한국시뮬레이션학회논문지
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• 제8권1호
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• pp.19-33
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• 1999

The fundamental issues to evaluate machine tools performance through simulation pertain to the physical models of the machine tool itself and of process while the practical problems are related to the development of the modular software structure. It allows the composition of arbitrary machine/process models along with the development of programs to evaluate each state of machining process. Surface roughness is one of the fundamental factors to evaluate machining process and performance of machine tool, but it is not easy to evaluate surface roughness due to its tribological complexity. This paper presents an algorithm to calculate surface roughness considering cutting geometry, cutting parameters, and contact dynamics of cutting between tool and workpiece as well as tool wear in turning process. This proposed algorithm could be used in the designed virtual machining system. The system can be used to evaluate the surface integrity of a turned surface during the design and process planning phase for the design for manufacturability analysis of the concurrent engineering.

• 전기학회논문지
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• 제58권10호
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• pp.1962-1967
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• 2009

This paper deals with a design of a platform to simulate PRT vehicle operational control algorithms using on-board embedded process board. The configuration of the platform is composed of the central control module, the station control module, man-machine interface and monitoring module. Since PRT system needs inherently very reliable vehicle operational control algorithm in order to avoid the impact between vehicles, it is very important to construct a simulation platform to test a designed vehicle operational control algorithm during the development process For the test of the proposed platform a path of the each moving vehicle is predefined in the central control system before the dispatch order is given to the vehicle. The simulation results show the effectiveness of the proposed simulation platform for test and evaluation of the PRT operational control algorithms.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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• pp.291-293
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• 1996

Logic simulation is playing a very important role for design verification as circuits are larger and more complicated. However unknown values in 3 value simulators may generate the X-propagation problem which makes inaccurate output values. In this paper, a new partitioning method and a new simulation algorithm are developed to deal with the X-propagation problem efficiently. The new algorithm can optimize simulation time and accuracy by controlling partition depth. Benchmark results prove the effectiveness of the new simulation algorithm.

• 한국시뮬레이션학회논문지
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• 제1권1호
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• pp.64-76
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• 1992

The DEVS(discrete event system specificaition) formalism specifies a discrete event system in a hierarchical, modular form. DEVSIM++ is a C++based general purpose DEVS abstract simulator which can simulate systems modeled by the DEVS formalism in a sequential environment. This paper describes P-DEVSIM++which is a parallel version of DEVSIM++ . In P-DEVSIM++, the external and internal event of DEVS models can by processed in parallel. For such processing, we propose a parallel, distributed optimistic simulation algorithm based on the Time Warp approach. However, the proposed algorithm localizes the rollback of a model within itself, not possible in the standard Time Warp approach. An advantage of such localization is that the simulation time may be reduced. To evaluate its performance, we simulate a single bus multiprocessor architecture system with an external common memory. Simulation result shows that significant speedup is made possible with our algorithm in a parallel environment.

• Journal of Astronomy and Space Sciences
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• 제30권1호
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• pp.1-10
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• 2013

An integrated orbit and attitude control algorithm for satellite formation flying was developed, and an integrated orbit and attitude software-in-the-loop (SIL) simulator was also developed to test and verify the integrated control algorithm. The integrated algorithm includes state-dependent Riccati equation (SDRE) control algorithm and PD feedback control algorithm as orbit and attitude controller respectively and configures the two algorithms with an integrating effect. The integrated SIL simulator largely comprises an orbit SIL simulator for orbit determination and control, and attitude SIL simulator for attitude determination and control. The two SIL simulators were designed considering the performance and characteristics of related hardware-in-the-loop (HIL) simulators and were combined into the integrated SIL simulator. To verify the developed integrated SIL simulator with the integrated control algorithm, an orbit simulation and integrated orbit and attitude simulation were performed for a formation reconfiguration scenario using the orbit SIL simulator and the integrated SIL simulator, respectively. Then, the two simulation results were compared and analyzed with each other. As a result, the user satellite in both simulations achieved successful formation reconfiguration, and the results of the integrated simulation were closer to those of actual satellite than the orbit simulation. The integrated orbit and attitude control algorithm verified in this study enables us to perform more realistic orbit control for satellite formation flying. In addition, the integrated orbit and attitude SIL simulator is able to provide the environment of easy test and verification not only for the existing diverse orbit or attitude control algorithms but also for integrated orbit and attitude control algorithms.